Cisco 400-007 Exam With Confidence Using Practice Dumps

For EIGRP to maintain loop-free alternate paths, the feasibility condition must be met:

A. The Reported Distance (RD) must be lower than the router's Feasible Distance (FD).

E. A feasible successor must exist (i.e., an alternate next-hop satisfying the feasibility condition).

This design allows immediate failover without recomputation, ensuring fast convergence — a critical CCDE v3.1 protocol design principle.

Why other options are incorrect:

B, C, D: Misstate the feasibility condition or confuse RD and FD relationships.

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The goal is to prevent AS 111 from being used as a transit AS.

The most effective method is to use an AS path access list to filter outbound BGP advertisements, allowing only prefixes originated from AS 111 (AS path contains only AS 111).

This ensures AS 111 only advertises its own prefixes and does not forward third-party prefixes between providers.

Why other options are incorrect:

A: AS-set is used for aggregation, not for transit prevention.

B: Local preference controls outbound path selection, not advertisement or transit.

D: Prefix list on inbound filters received prefixes, but does not prevent transit.

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